Rescue workers in China say there is renewed hope of finding survivors five days after water flooded a coal mine trapping 153 workers.
Tapping and possible shouting has reportedly been heard about 250 metres underground.
If confirmed, the noises would be the first signs of life since the shaft was inundated with up to 140,000 cubic metres of water.
The accident at Linfen happened when workers digging tunnels broke into an old mine filled with water.
In a separate incident on Thursday, a dozen people were killed in a gas explosion at a mine near the central city of Luoyang.
Officials say a search is continuing for 32 other workers still missing.
China’s coal mines are the world’s deadliest, despite a massive government drive to reduce fatalities.
But the large number of people involved in accidents this week has raised further questions about safety standards.